Search results for "Emerging"
showing 10 items of 640 documents
A multimedia approach to the efficient implementation and use of emergency plans
2004
Because of the complexity of emergency procedures, the stressful situations during which they're executed, the emergency plan must be meticulously designed so that safety managers can quickly find needed information. Regardless of the complex procedures it describes and the trying situations where it would be used, the plan's success is always measured by how effective the evacuation is. Thus, safety-conscious organizations continually try to improve their emergency procedures and the way they present them in the emergency plan. Integrating incoming information during an emergency and correlating this information with the plan's procedures is a manual task for many safety managers. The dang…
Used and interaction in technological platforms of open source to improve the linguistic competence in computer engineers
2017
The higher education through virtual environment is students centered oriented to the interactive learning, in situations to be closer to the real world; for that reason, teachers must have new communicative competences, nonverbal and with a learning innovative approach which allows to guide their students in the complex process of acquiring knowledge even more in a foreign language. In the same context, the use of technologic platforms of open code is becoming in the best way to give solutions which meet the actual needs of the process of acquiring a second language; on this basis, the present research is focused in the analysis and use of Open Source tools as alternative of complementary …
Correlation between mutation rate and genome size in riboviruses: mutation rate of bacteriophage Qβ.
2013
Abstract Genome sizes and mutation rates covary across all domains of life. In unicellular organisms and DNA viruses, they show an inverse relationship known as Drake’s rule. However, it is still unclear whether a similar relationship exists between genome sizes and mutation rates in RNA genomes. Coronaviruses, the RNA viruses with the largest genomes (∼30 kb), encode a proofreading 3′ exonuclease that allows them to increase replication fidelity. However, it is unknown whether, conversely, the RNA viruses with the smallest genomes tend to show particularly high mutation rates. To test this, we measured the mutation rate of bacteriophage Qβ, a 4.2-kb levivirus. Amber reversion-based Luria–D…
Variability in the mutation rates of RNA viruses
2014
ABSTRACT: It is well established that RNA viruses show extremely high mutation rates, but less attention has been paid to the fact that their mutation rates also vary strongly, from 10-6 to 10-4 substitutions per nucleotide per cell infection. The causes explaining this variability are still poorly understood, but candidate factors are the viral genome size and polarity, host-specific gene expression patterns, or the intracellular environment. Differences between animal and plant viruses, or between arthropod-borne and directly transmitted viruses have also been postulated. Finally, RNA viruses may be able to regulate the rate at which new mutations spread in the population by modifying f…
Variation in RNA virus mutation rates across host cells.
2014
It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10−6 to 10−4 substitutions per nucleotide per round of copying (s/n/r) and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV), which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly…
Negative differential resistance in carbon nanotube field-effect transistors with patterned gate oxide.
2010
We demonstrate controllable and gate-tunable negative differential resistance in carbon nanotube field-effect transistors, at room temperature and at 4.2 K. This is achieved by effectively creating quantum dots along the carbon nanotube channel by patterning the underlying, high-kappa gate oxide. The negative differential resistance feature can be modulated by both the gate and the drain-source voltage, which leads to more than 20% change of the current peak-to-valley ratio. Our approach is fully scalable and opens up a possibility for a new class of nanoscale electronic devices using negative differential resistance in their operation.
High-Yield of Memory Elements from Carbon Nanotube Field-Effect Transistors with Atomic Layer Deposited Gate Dielectric
2008
Carbon nanotube field-effect transistors (CNT FETs) have been proposed as possible building blocks for future nano-electronics. But a challenge with CNT FETs is that they appear to randomly display varying amounts of hysteresis in their transfer characteristics. The hysteresis is often attributed to charge trapping in the dielectric layer between the nanotube and the gate. This study includes 94 CNT FET samples, providing an unprecedented basis for statistics on the hysteresis seen in five different CNT-gate configurations. We find that the memory effect can be controlled by carefully designing the gate dielectric in nm-thin layers. By using atomic layer depositions (ALD) of HfO$_{2}$ and T…
A more targeted approach to foreign direct investment: the establishment of screening systems on national security grounds
2018
The process of liberalization of international trade and of Foreign Direct Investment (FDI) has constituted a broadly accepted trend during the last few decades and FDI inflows have expanded constantly since the end of the 1980’s. However, signs of a certain crisis of the positive and one-way attitude towards international trade and FDI exist nowadays. The increase in the flux of FDI coming from developing and emerging countries to developed economies, the sudden relevance of foreign sovereign investors, the changing environment for national security or the quest to protect technologies and sectors of the economy considered vital for the host country, its sovereignty and competitiveness are…
Viaggi nell’immaginario: il turismo virtuale nel sito UNESCO di Tarragona
2023
Le nuove tecnologie hanno trasformato in modo radicale non solo la geografia come disciplina, ma anche le geografie del mondo. Il digitale ha assunto, infatti, un ruolo di mediazione sempre più pervasivo nella produzione dello spazio, come delle conoscenze e degli immaginari geografici. Le possibilità offerte dal virtuale, in particolare, offrono oggi un contributo decisivo nella comunicazione dei significati attribuiti ai luoghi e rispondono in modo sempre più efficace ai bisogni emergenti del settore turistico. Le esperienze di visita mediate dal digitale mirano a coinvolgere i sensi e risultano efficaci quando promuovono immersioni rigorosamente realistiche. Nel quadro di queste riflessi…
Solubility and diffusion of nitrogen in maltodextrin/protein tablets.
2002
The gas transport properties of compacted tablets consisting of an amorphous mixture of maltodextrin and sodium caseinate were studied by dissolving nitrogen gas in the tablets and then determining the gas release over time as a function of temperature and water activity. Gas was dissolved in the tablet matrix by heating the tablets under pressure, generally to temperatures above the glass transition temperature of the matrix, holding them at these conditions for a specified time and then rapidly cooling them while maintaining the external pressure. The solubility of nitrogen was found to be largely determined by the free volume of the matrix, which in turn can be influenced to some degree …